Can the American economy afford clean energy? Not all that long ago, the prevailing sentiment was "no." Today, the buzzwords are "green economy," and there's a growing realization that "green" means not only environmentally friendly, but also profitable and full of opportunity for job creation.

A confluence of trends is behind the shift in attitude. For one thing, energy prices last year became difficult to bear, and Americans started clamoring for alternatives. More and more people are also coming around to the viewpoint that the country's dependence on foreign oil is not sustainable, and is a growing threat to national security. Add to that the feeling that time is running out for environmental fixes - that the planet can wait no longer for a solution to climate change. What's more, alternative energy technologies just keep getting better, making economically feasible everything from wind power to fuel made from crop waste. Finally, the economic downturn has fueled the need for new jobs.lots of them.

Clean energy would seem to provide solutions to all of these needs, but what kinds of opportunities are out there? What kinds of jobs? And where will they grow? The answers provide some much-needed encouragement in a down economy - there are jobs to be had, plenty of them. And they're going to be sprouting all over the country, including in some of the areas that are hurting the most.

"Clean energy is an enormous opportunity for U.S. companies, as big as if not larger than the tech boom of the 1990s," says Daniel Goldman, executive vice president and chief financial officer of GreatPoint Energy. "We're talking about a trillion-dollar industry. I don't think the politicians have quite woken up to it, the investors are just starting to wake up to it, but entrepreneurs and technology developers are in it."

"I think it's going to be a long-term business; it's not going to be a short-term phenomenon," Todd Filsinger, head of PA Consulting Group's Energy Capital Markets practice, says of clean energy. Filsinger co-chairs the Coalition for Green Bank, a consortium of energy industry developers, manufacturers, investors, financial advisors, and consultants working to create jobs and foster economic development by unleashing private investment in renewable energy. "The prospects are immense, and think of the technology jobs that will be created," he says.

Diverse Opportunities in Clean EnergyClean energy goes by many names - sustainable, renewable, green, alternative - and includes a host of different technologies. It might be energy created through the power of wind; fuel created through the conversion of crop waste; power from the sun; natural gas created from coal; energy from trash that otherwise would be landfilled. The common denominator is that clean energy replaces energy that was formerly generated through not-so-clean traditional processes, such as the combustion of coal.

Just as the technologies are diverse, so are the ways clean energy can benefit local communities. Economic development surrounds not just the actual generation of energy, but also the many activities involved in supporting that generation, including the development and manufacture of related equipment, the distribution of energy, and the collection of the raw materials used by some of the processes.

Take wind power as an example. It has quickly become a high-growth business, with wind farms on the drawing boards in many parts of the country. That's driving demand for wind turbines - and the hope is that an increasing share of them will be made in America. At a recent wind power conference in Chicago, attendees spoke of the improving policy climate. Vestas Wind Systems A/S is developing manufacturing here after years of waiting for the right policy environment, and Emergya Wind Technologies dangled the prospect of at least 800 U.S. manufacturing jobs. GE, meanwhile, was building 10 turbines a week just a few years ago but now ships 13 a day.

Then there are the towers upon which the turbines are installed. Last year, DMI Industries decided to add some 225 jobs to its plant in Tulsa that builds towers for turbine-makers such as GE. "The demand for wind energy is helping us grow," John Erickson, CEO of parent company Otter Tail Corp., said in announcing the expansion. "As a nation, we only use about 1 percent wind energy now, and many think it will grow to 15, 20, or 25 percent."Goldman's company has developed a process that converts coal, petroleum coke, and biomass into pipeline-quality natural gas, and is gearing up to locate its first commercial production facility. GreatPoint Energy, he says, is building a bridge from the traditional energy business to the future of clean energy - creating new opportunities while still saving traditional jobs. "One of the big concerns as we move to clean energy has been whether we're going to destroy jobs in the old industry," he observes. "We can actually take coal, turn it into a clean fuel, and keep coal mining jobs."

Jack Oswald, meanwhile, is finding new markets for biomass such as crop waste and wood chips. He's CEO of a company called SynGest and has been a contributing member of the President's energy and environmental policy advisory group. He also serves as a delegate to the U.S.-China Clean Energy Forum and is a founding member of the Clean Economy Network.

"We can now make competitive, advanced biofuels using crop waste or wood chips," he says. SynGest's initial product is a nitrogen fertilizer, but the technology is flexible. "We can turn biomass into a synthetic gas and convert it to lots of kinds of products. We can change the back-end and produce ethanol, gasoline, and diesel."In this case, there's the potential for jobs linked not only to the actual production, but also to the provision of the feedstock that supplies the plant. Agricultural operations can win by changing their processes; for example, harvesting and then selling both the corn and the cob. "When that becomes the norm, we'll have a lot of opportunities," Oswald says.

And these are opportunities that can grow right in the heartland of the country, including many places hit hard by the current economic downturn. "There are a lot of manufacturing facilities that can be retooled for these technologies," Oswald says. "Some of the winners will be places that have lost a lot of manufacturing jobs, especially those that have lost jobs fairly recently. A lot of the new companies are going to the Midwest because of the economy."

Goldman expects GreatPoint Energy to create jobs in such places as Indiana, Illinois, Montana, Wyoming, and Texas. "We have taken the technology and tested it at a pilot plant in Des Plaines, Illinois, and we've built a demonstration facility in Massachusetts," he says. The Massachusetts project created 60 jobs, plus more than 500 construction jobs when the $40 million facility was being built.

"As far as components, one of the target areas will be Detroit," Filsinger suggests, referring to the manufacture of clean-energy equipment such as wind turbines. "You have a lot of need for job creation there, a lot of people who have manufacturing experience, and also a lot of manufacturing facilities that can be converted."

Filsinger points to potential jobs driven by the push for a Green Bank or Clean Energy Bank, which would funnel government investment funds into promising projects. "When the Clean Energy Bank is passed through Congress, it'll make available close to $50 billion a year for green infrastructure - not just solar or wind but distribution and manufacturing. And when you look at investment, every $50 billion you invest in clean energy is going to create about a million jobs."